Surface configuration of a key



FIG. 1 is a front view of a surface configuration of a key according to my novel design;

FIG. 2 is a rear view of the surface configuration of a key according to my novel design;

FIG. 3 is a side view of the surface configuration of a key according to my novel design; and,

FIG. 4 is a top view of the surface configuration of a key according to my novel design.

The broken lines are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a surface configuration of a key, as shown and described. 